Automatic overload and power releasing device



May 29, 1945. v U LAWN 2,376;-9,25

AUTOMATIC OVERLOAD AND POWER RELEASING DEVICE Filed April 2, 1943 3 Sheets-Sheet l Hail.

INVENTOR Jb/m J Air/A J. J. LAVI N May 29, 1945.

AUTOMATIC OVERLOAD AND POWER RELEASE G DEVICE 3 Sheets-Sheet 3 Filed April 2, '1943 absorbing feature that are Patented May 29, 1945 n'ro rrc QVERLOAD AND POWER imnnasme'nnvmn resh-.1, Le i ch me, f Appmauon A ril 2, 1943; SerialNoi14f8'L65t (Clltlflzmfifi) t I team. My invention relates to an improvementfih sa ety devices and onsists of n autcmaticio e load and power releasing device. I

The purpose of my inventien s to proyide' -a safety device to protect power driven machines to a predetermined ever.- load, my device mechanically disengages the driven. unit from the driving un and thus he overload on the d iv nshait s re e sed! a f h p ra d mach ne is ne i w h i is also desirable to shut on the moto my invert tion may e nrovidedwith a mete cut-eff which whe e y the paw wli hreleases,' the driven en my may a so protrude and a ti at a wi ch against damage resulting from overloads; When "a. machine is subjected automatically shuts oif the motor immediately (after the units are disengaged. In this way the device periorms double safety funct By i mechanical power release it disengages the drive ing unit from the driven unit, and by its motor cut-off feature it cuts off the-ppwer. I I

' My dev e is provided with a spring leadc'ar ying O' ruction w e eby th driving power conveyed to the machine by springs instead of by rigid parts. I have termed this a because byv it" the extra loads, always p sen when ame h n is start ed, can e a r ed Wi h u e danger f hav ng the extra starting loads release the clutch.

,At the present time, many machines re me 'vided with safety devices which an excessive ove load sh s p he motor u ua ly eeri tinnes torun hich wastes p wer and m ght damage the motor. Mvdevice r eliminates the shearp'in assembly. i

When the machine is repairedfloi freed 'of obstructions, my device is reset by applying normal pressure to a protruding trigger. 7'

The principalobi t of h present invention is to provide an improved we releasing v e of the type described that s sp i oaded and a p to carry sudden overloads or other ordinary variations in load which mayoccu bu which whena p sitive e ven lnad occurs, wi l s n ge the drivin sha t from a pulley through which the power is being transmitted. Y t

A further object, of the invention is'to provide an improved constructicn of the type described wherein a ratchet and pawl are utilized to transmit the driving power from thegshaftto the pul- 'l y, said pawl having a mecha ism associated therewith which is directly moved by thedriven pull y when an overload, occurs to d s nga the driven pulley against spr n pressur A iurther object sh ck au oma ic 'ove l'oadan which may nntr l amote i r Other o jects and advan ages will be m reape parent item the renew ng descript on wherein eferen e, .ishad tep he a ompanying three sheets Qt awin s pnn which 3 f H e. ll s. a side. e evatieha v ew c f yfi mst ipp g and starti g of proved device showing the driven shaft extendihetherefrom;

r z i. a sectional new insi e (lithe me a- F 3 s a irasme taryse tiehaljview Qt a t p 'men b r which I employ and. is ta en on. the l n Fisiis a verti al sectiona view through, the t e'mecha ism ta en gene ally .011 the l e A e-W4 time. 2;

fig. 5 is ase mentsmag nta show-- hg the 'ssle l n 'ahdlasseciated me ism,

of the ,mveht ehiste provide in a construction of the typehescribed'means 46,. which is keyed .to

taken gene all on the l ne 5-6 of F g.-

Fis- 6 s a similar I sectio a view or the paw and associ ted 'tahengenermy o the linefi fi Dims-2: e

g. 7 is a cro ctio al view sh win the sp ei l spr ng cadedfpu ey and associated-pa ts r and taken .ohthe'hne -1 of Fis nd F g. 3 is, a similar se tional view taken on the line er-leafl ts; 1 b leqkihgin the oppesite dir cti n f om Fig.,-7}howin thepawl and ratc t suppo t m r ber-end'associated parts,

In he embodim nt of the invention which I havewchcs n to-il1ustrate,;in in; 1" I have shown a driv n shaft I10, whi h may have the pu y 1 and-p wl and ratchet frame mechanism It c .nected to th hde thesame. Theratc et wh l the end of the SDM'MQQH- stitutes one end of the assembly with t'he collar -1 ,ncs t c ihe th Pulley 1 0.1 reduced sh u vtie oi the hub 22 of the mem r 4- he collar isihe cl in'rpesition by suitab e lien head screwri m er 2 i 1 5 most clear y shownin i s. 1,1 and r ti drawings, the pulleyll may-be proyidedwlth a gro ve 26 to receive a; m y transmit the drive to i s d nat ro the driven'shaft, 10 The pulley 12 may alsobe formed with a ylindricai i y Witmnwhich pair ,Qi. ,il6 1 Spring members '32: and. 34 are positioned One end ofeachof-thesprings 32 and 34 may be fastened to'bolt'members; 36 and respectively, mithe e her nd h V-be lt 2 which v-teit vl bars 40 and 42 which extend downwardly into the groove 30 from the back plate 44 of the member l4. The pulley l2v is also'formed with a pair of arcuately shaped grooves 46 and 48 with-jin which the stop members 50 and 52 on the back 44 of the member l4 are received. The pawl push-out and stop assembly 54 also extends into the cavity 46. I

Referring now to Fig.2, I have shown the star or ratchet wheellfilkeyed to the end of driven shaft I and engaged bye pawl member 58 which is aligned with anopening 60 in the housing I}? that covers the pawl and ratchet mechanism and is secured to the back wall-'44 by the screw members 63. The pawl 58 may have outwardly extending arm portions 64 which connect with parallel arm members 66. The arm members 66 (see Figs. and 6), are positioned in --parallel grooves 68 in a pair of upstanding ridges upon the member I4. They may be connected at theirli extended ends by an arcuately shaped portion .12 which is provided with'aslot to receive a link 14 of a toggle member 115." The end of the link may be pivoted on the pin 18. The opposite end of link 74, isconnectedby a. pin 80 to a similar lihkimemebr BZ that is pivoted upon pin 84 on a ring member 86 which is secured by screw members 88 to. the wall 44.. A stopmember 90 pro- 1 vided with an adjustable screw. 92 (see Figi 3); s is mounted on the wall to'efiect a limit stop for the toggle mechanism shown. ,j i i With the link-mechanism alignedjas shown in Fig. f2,"the pawl 58 normallyengages one of the; teeth of the ratchet member'- l6 and in thls po- 1 sitioneifectively locksthe entire assembly to the driven shaft I0. When there is an overload on the pulley [2, the pin 94, which is mounted" in oneofthe row of tappedholes 96 in a'vertical it can be seen that I have provideda very efiective and eflicient overload and power releasing device whereby I utilize a pair of coiled springs to permit of slight variation'in load, yet which, when an overload is reached, will positively unlock and disengage the driving pulley from the drivenshaft. I

I At the'same time, the pawl member which is actuated to efiect the release of the driving pulley is also moved. outwardly in a positive manner so that a switch or other mechanism can be shut off by engagement with the same.

The mechanism can of course be reset by press- -ing in' the' pawl 58 so that all the mechanism is reset-to the position shown in Fig. 2. By means of the series of tapped opening 96, the amount of spring tension which is desired before release canbe varied to suit the individual requirements.

While I have shown and described a specific embodiment of the invention, it will be apparent to those skilled in the art that changes and modi- -ficationsimay be made inthe exact details shown. I do not wish to limit myself in anyparticulan protect by a rather what I' desire to secure and Letters Patent of the United States is? Apparatus of the class described including a driven shaft, a ratchet wheel secured thereto, a pulley rotatably mounted on said'shaft, a pawl member associated with said pulley and adapted to engage said ratchetwhe'el, said pawlmember having sideward extensions, guide members associated with said pulley. having parallel grooves therein, said extensions entering said grooves, an

. arm connecting said extensions at one end therewall 98 of the pulley l2 will bemoved against the direction of rotatibnof the shaft). and

3 press against. the same at its center" pivot 80,

thereby rotating the samecounter-clockwise and is moved outwardly it may press against a switch 1 passing through the arcuate slot 10in the back i 3 wall 44 will eventually reachtoggle link 16v and (not shown) and shut 'ofi a motor or other mechanism"which is controlled'by such switch. Means for assisting guiding and stopping the l movement of pawl 58 may include trigger mem- 1 ber I54 which. is mounted in a'cylindrical'hous I ingJllB the back wall 44. The'trigger mem- 3 ber "N54 is normally pressed outwardly by a compressionspring'lflil and enters the slot I ID in the pawl 58 thereby both'as'sistin'g in'its movement outwardly and in providing an efiectivestop at its outwardlimit.

Iprovid'e means for normally holding the toggle mechanism in the operative position'shownin Fig. 2. This means may include a spring loaded lever H2 which is pivotallymounted upon abolt member .l l 4 that entersfia "cross-bar. H6,"which ispositioned between the ridges 10 of the member l4. Thelever H2 may have a coiled spring spring I] 8.

the construction I have. described member H8 connected between the same and a q bolt member I20 which extends through an open:-

of, a'togglemechanism associated therewithand means 11, p eyfommov'ing said toggle mechanism to release said v pawl from engagement with said ratchet wheel. 1

2. Apparatus of the class'described including a driven shaft, a ratchet'wheel secured thereto, a

pulley rotatably mounted on said shaft, a pawl member associated with said pulley and adapted to engage said ratchet wheel, said pawl member having sideward extensions, guide members associated with said pulley having parallel grooves therein, said extensions entering said grooves,

an arm connecting said extensions at one end thereof, a toggle mechanism associated. therewith and means on said pulley for moving said toggle mechanism to release said pawl from engagementwith said ratchet wheel, said'means including a pin member adapted to engage said toggle mechanism to disengage said pawl member from said ratchet wheel.

3. Apparatus of the class described including a driven shaft, a ratchet wheel secured thereto, a pulley rotatably'mounted on said shaft, a pawl member associated with said pulley'and adapted to engage said ratchet wheel, said pawl member having sideward extensions, guide members associated with said pulley having parallel grooves therein, said extensions entering said grooves and slidable therein, an arm connecting said extensions at one end thereof, a toggle mechanism associated therewith and means on said pulley for moving said toggle mechanism to release said pawl from engagement with said ratchet wheel, and a stop member engaging said pawl to eifect a predetermined movement of the same.

4. Apparatus of the class. described including adriven shaft, a ratchet wheel secured thereto, a'pulley rotatably mounted on, said shaft, a generally rectangular frame memberassociatedwith said pulley, a, pawl member mountedqon said frame member 'andadapted to engage said ratchet wheel, said frame member having sideward extensions, guide members as'sociated with said pulley having parallel grooves therein, said extensions entering said grooves and slidable therein, an arm connecting said extensions at one end thereof, a toggle mechanism associated therewith and means on said pulley for moving said toggle mechanism to release said pawl from engagement with said ratchet wheel."

5..An automatic overload and power releasing device including a driven shaft,a ratchet keyed to the end of said shaft, said ratchet engaging a pawl, a generally rectangularly shaped frame carrying said pawl, a pair of guides, a pair of the parallel sides of said frame s'lidably mounted in said guides, a housing for supporting said guides and enclosing said mechanism, said housing having a collar surrounding said shaft, a pulley rotatably mounted upon said collar, means including said pawl connecting said pulley and said ratchet whereby rotation of said shaft is secured from said pulley through said ratchet.

6. An automatic overload and power releasing device including a driven shaft, a ratchet keyed to the end of said shaft, said ratchet engaging a pawl, a generally rectangularly shaped frame carrying said pawl, a pair of guides, a pair of the parallel sides of said frame slidably mounted in said guides, a housing for supporting said guides and enclosing said mechanism, said housing having a collar surrounding said shaft, a pulley rotatably mounted upon said collar, means including said pawl connecting said pulley and said from said pulley through said ratchet and spring means connected between said pulley and said pawl for permitting a degree of overload.

7. An automatic overload and power releasing deviceincluding a drivenshaft, a ratchet keyed to the endof said shaft, said ratchet engaging'a,

pawl, a generally rectangularly shaped frame a carrying said pawl, a pair of guides, a pair of the parallelsides of said frame 'slidably mounted, in said guides, a housing for supporting said guides and enclosing said mechanism, said housing having a collar surrounding said shaft, a pulley rotatratchet whereby rotation of said shaft is secured ably mounted upon said collar, means including said pawl connecting said pulley and said ratchet whereby rotation of said shaft is, secured from said pulley through said ratchet, said pawl adapted when disengaged from said-ratchet to move. only a predetermined distance.

8. Apparatus of the class described including adriven shaft, 'a ratchet wheel secured thereto, a pulley rotatably mounted on said shaft, a pawl member associated with said pulley and adapted-to engage said ratchet wheel, said pawl member hav ing sideward extensions, guide members associated with said pulley having parallel grooves therein, said extensions entering said grooves and slidable therein, an arm connecting said extensions at one end thereof, a t ggle mechanism associated therewith and means on said pulley for moving said toggle mechanism to release said pawl from engagement with said ratchet wheel, and a spring pressed stop member engaging said pawl to effect a predetermined movement of the same.

JOHN J. LAVIN. 

